JP2002302679A - Carbonization method for sludge, etc. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbonization method for sludge, etc., whereby an amorphous object, such as sewage sludge, having high water content and viscosity can be continuously carbonized while markedly reducing the fuel consumption in the carbonization. SOLUTION: (1) A water-containing amorphous sludge is mixed and kneaded with a mineral powder to reduce the water content, and the mixture is caused to pass through a molding machine to be given a section with a fixed shape; and after the surface of each of sludge with a fixed shape is made so that it is not adherent or sticky to that of other same sludge, the sludge with a fixed shape is continuously fed into the upper side of a cylindrical rotary kiln 1 which has a spiral transport wall 2 formed on the inside peripheral surface and an agitation wall 3 formed on a part of the transport wall 2 so as to cross the transport wall 2. (2) A flame is blown from the lower side of the rotary kiln into its inside, and when the sludge is ignited, the blowing of the flame is stopped. (3) A gas is sucked from the upper side of the rotary kiln, is made harmless, and exhausted. (4) By conducting all the above operations (1)-(3), a carbonization product of the sludge is discharged from the lower side of the rotary kiln.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously and continuously carbonizing sludge and other combustible wastes using rotary giraffe.

[0002]

2. Description of the Related Art In general, a rotary kiln blows a flame into the inside of a cylindrical body from a lower side thereof when rotating a cylindrical body having a fire-resistant inner surface slightly inclined from horizontal and rotating at a low speed. It is known as a method for feeding a raw material such as a cement raw material from the upper side and firing the raw material.

Recently, there has been proposed a method of treating combustible waste using rotary giraffe. However, the proposed method has a high water content such as sewage sludge, and is irregular and has a low viscosity. It is almost impossible to efficiently carbonize a high processing target. In addition, not only in the case of irregularly shaped waste such as sewage sludge, but also in the treatment of regular waste,
The flame blown into the inside of the rotary kiln from the lower side has a drawback that the fuel cost is significantly increased because it is kept blown during the processing.

[0004]

In the present invention, therefore, not only can the subject having a high water content, such as sewage sludge, be amorphous and have high viscosity, be continuously carbonized, but also the fuel consumption in the process can be significantly suppressed. An object of the present invention is to provide a method for treating sludge and the like.

[0005]

Means for Solving the Problems The constitution of the method of the present invention aimed at solving the above-mentioned problems is as follows: (a) Ore powder is kneaded with amorphous sludge containing water to lower the water content. In this state, the shape of the cross section is shaped through a molding machine,
After making each of the shaped sludges into a surface state in which they do not adhere or stick to each other, the shaped sludge is transferred to a spiral conveying wall on the inner peripheral surface and the conveying wall to a part of the conveying wall. Above the cylindrical rotary kiln having a transverse stirring wall, the rotary kiln is continuously supplied in a predetermined unit amount while rotating the rotary kiln. A flame is blown into the inside of the rotary kiln from below, and when the sludge is ignited in the rotary kiln, the blowing of the flame is stopped. (C) A rotary kiln placed in the state of (a) or (b) above. (D) discharging the sludge carbide from the lower part of the rotary kirin by performing the operations (a) to (c) above by sucking the gas inside the rotary kiln from above, detoxifying and exhausting the gas. It is characterized by the following.

In the present invention, in order to form a surface state in which the formed sludge does not adhere or stick to each other, for example, the surface is made almost dry by using an appropriate heating means or a blowing means or a heating and blowing means. You can also.

According to the present invention, when carbonizing solid or fixed-size combustible waste other than sludge, the surface of the waste is treated with minerals such as granite and quartz porphyry. Can be carbonized by applying the above operations (a) to (d).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the method of the present invention will be described with reference to the drawings. FIG. 1 is a side view schematically showing a part of a carbonization apparatus for carrying out the method of the present invention, and FIG. 2 is a side view of a transfer wall in the carbonization apparatus shown in FIG. Is a partially enlarged perspective view of a transfer wall provided with different stirring walls, and FIG. 3 is a cylinder 1 showing a state in which the transfer wall shown in FIG. 2 is used and carbonization is performed by the apparatus shown in FIG.
FIG. 4 is a cross-sectional view of the cylinder 1 showing a state where the cylinder 1 is rotated from the state shown in FIG.

In the figure, 1 is about 10 m in length and 40 mm in inner diameter.
It is a tubular body made of steel pipe of about 50 cm. Here, a plurality of tubular units having a required unit length are connected to each other at an outer flange-like joint to form a single tubular body 1.

Reference numeral 2 denotes a transfer wall provided on the inner surface of the cylindrical body 1 so as to form a spiral over the entire length of the cylindrical body 1. The transfer wall 2 is located on the front side (left side in the figure) of the full length of the cylindrical body 1. Is provided with a stirring wall 3 in a direction transverse to the conveying path formed by the spiral conveying wall 2.

Reference numeral 4 denotes a heat insulating layer provided on the outer surface of the entire length of the cylindrical body 1. The rotary kiln body Kb is formed by the above-described structure of the cylindrical body 1 to the heat insulating layer 4.

The rotary kiln body Kb is provided at three locations in the longitudinal direction, specifically, at both front and rear ends and a central portion.
Each of the belt-shaped rings 5 is attached, and the lower part of each ring 5 is supported by rotatable support rollers 6, 7, and 8, and at least one of the rollers is driven by a motor or the like as a driving roller, whereby this rotary kiln body Kb Rotates at a fixed position on the rollers 6 to 8. Reference numerals 6a, 7a, and 8a denote roller frames, and BF denotes a base frame on which the roller frames 6a to 8a are fixed. In the illustrated example, the rotary kiln body Kb
Is provided in a substantially horizontal attitude, but may be provided with a downward slope (the right side in the figure is downward).

Reference numeral 9 denotes a flame gas burner disposed below (to the right of the figure) the rotary kiln main body Kb, and has a flame injection port 9a of the burner 9 facing the inside of the main body Kb. A pit P is provided in front of the gas burner 9 for disposing a container 20 for accommodating the carbonized material.

Numeral 10 is a charging means for the processing object disposed above the rotary kiln main body Kb, specifically formed by a conveyor or a hopper with a shutter, and a sewage to be treated inside the rotary kiln main body Kb. It is formed so that waste such as sludge can be continuously supplied in a unit amount / hour.

Reference numeral 11 denotes a pre-processing section disposed on the front side of the charging means 10, and the pre-processing section 11 comprises a forming section 11a and a surface drying section 11b. In the forming section 11a, when the treatment target is sewage sludge, although not shown, a mixer for kneading the ore powder with the sludge and a function for continuously discharging the kneaded mixture with the mixer from a discharge nozzle were provided. For example, it is formed by a pellet molding machine. In addition,
In addition to the pellet molding machine, a molding machine having the same function as this can be used. In addition, this forming part 11a
When the object to be treated is a solid such as a fir husk or a piece of wood, it is formed by, for example, a ribbon mixer or the like having a function of coating the outer surface with ore powder. The pre-processing unit 11 having these functions with different functions is selectively or in parallel arranged above the rotary kiln main body Kb depending on the processing target. In the surface drying section 11b of the pretreatment section 11,
The sludge formed and shaped by the forming unit 11a is received, and the surface of the sludge is dried by a heating means or a blowing means or by a heating and blowing means. As such means, for example, a drum-type dryer is used, but other heating and blowing devices may be used as long as they have the same function. The sludge whose surface has been dried in the surface drying section 11b is conveyed to the charging means 10 by a belt conveyor.
The surface of each sludge thus shaped is dried when the sludge is put into the charging means 10 or when the sludge is conveyed inside the rotary kiln body Kb. In order to prevent
In addition to drying the surface, if there is a method in which each sludge does not adhere or stick, it is obvious that the method can be used.

Numeral 12 denotes exhaust processing means for sucking gas existing inside the kiln during the processing step and detoxifying the gas at the upper open end of the rotary kiln main body Kb. ing. Of these, 12a is a combustion block with an afterburner and a combustion chamber for burning black smoke, off-flavors and odors that may be generated depending on the treatment object, 12b is a cooling block for cooling exhaust gas emitted from the combustion block 12a, and 12c is A neutralized block filled with slaked lime to neutralize Cl components and the like in the cooled exhaust gas and activated carbon to increase the dust collection efficiency of the filter cloth in the next filter block. Pulverized sludge coal that has been carbonized can be used. 12d
Is a filtration suction block including a filter block for filtering ash and dust in the exhaust gas and a suction block using a cyclone or the like as cooling means.

As described above, an example of a carbonization apparatus using a rotary kiln for implementing the method of the present invention is constituted.
Next, the carbonization of sludge using this apparatus will be described.

First, in the pretreatment section 11, ore powder is mixed with the dewatered sewage sludge to be treated at a ratio of about 3 to 8% by volume, and the whole is kneaded to reduce the water content of the sludge. In the same manner as the above, it is supplied to the input means 10 by extruding from a molding machine.

On the other hand, for the rotary kiln body Kb,
Prior to the loading by the loading means 10 of the processing object, by rotating the driving rollers among the rollers 6, 7, 8
The kiln body Kb is preheated by blowing a flame from the burner 9 while rotating the kiln body Kb in the feed direction by the transfer wall 2. This preheating is performed for about 20 minutes, and the above-mentioned treatment target (sludge) is supplied to the charging means while the flame is being blown.
From 10, it is continuously charged above the rotary kiln body Kb.

The sludge to be charged is the rotary kiln body Kb
Is sequentially fed to the lower side of the kiln body Kb by the action of the transport wall 2 inside. In this feeding, the sludge is repeatedly lifted and dropped on the ceiling side of the kiln body Kb by the action of the wall 3 at the portion where the stirring wall 3 is provided, and drying is promoted. In addition, at the time of feeding, since the flame is blown from the burner 9 into the kiln body Kb, the water in the sludge evaporates immediately, and the water content of the sludge itself decreases toward the downstream side of the rotary kiln body Kb. Almost gone. Further, at this stage, the exhaust processing means 12 is also already driven to suck the inside of the rotary kiln body Kb.

As a result, the dried sludge that has been thrown into the rotary kiln body Kb and conveyed to the lower side by the rotation of the main body Kb and has reached the lower end portion is converted into a combustible gas component from the burner by the burner. Ignition by the flame of No. 9. In the present invention, when the sludge thus ignites its gas component, the blowing of the flame from the burner 9 is stopped.
Even if the blowing of the flame is stopped, the combustion state of the gas component does not change, but the ignited portion gradually goes up inside the rotary kiln main body Kb (toward the processing material input side). Localization (combustion position F) at a position about 2 m to 3 m from the part, where the combustion of the combustible gas components released from the sludge continues. At this time, the internal temperature of the rotary kiln body Kb is about 800 ° C. to 830 ° C.

As described above, the combustible gas component released from the inside of the sludge burns inside the rotary kiln body Kb. The mechanism of carbonization of the sludge by this combustion will be described. What seems to be burning the treated material M (sludge) at the fixed position F inside the rotary kiln body Kb is the combustion of the combustible gas released from the inside of the treated material M. The reason why this combustion is continued at the fixed position F is that, inside the rotary kiln body Kb, sludge as a processing object that is sequentially sent from above to the fixed position F due to the rotation of the rotary kiln body Kb is just discharged. This is because the combustion condition of the combustible gas released from the inside of the sludge at the position F is set. That is, the oxygen required for the combustion of the combustible gas is constantly supplied from below (downstream) the rotary kiln body Kb (the suction action of the exhaust treatment means 12), but the supplied oxygen is almost at a fixed position F Is consumed by combustion in
This is because the sludge itself lacks oxygen for burning in the rotary giraffe body Kb.

As a result, in the rotary kiln main body Kb, the combustible gas continues to burn at the fixed position F, and the inside of the kiln main body Kb is subjected to the suction action of the exhaust treatment means 12. The upstream side from the combustion position F is almost oxygen-free or oxygen-deficient, and the oxygen sucked downstream is consumed by the combustion at the fixed position F, and becomes oxygen-deficient or approximate. On the other hand,
The interior of the rotary kiln body Kb is maintained at about 800 ° C. to 830 ° C. except for the lower end (outside air inflow end) by using the combustion maintained at the fixed position F as a heat source. The treated material M (sludge) transported inside the rotary kiln body Kb in such an oxygen environment and a temperature environment is thermally decomposed without burning itself, and its carbonization proceeds. From the lower end of the rotating rotary kiln body Kb, the carbonized sludge falls into the container 20 of the pit P, where the carbide is collected.

In the case of sewage sludge, since the water content varies by about 10% depending on the season, even if the sludge is shaped in the pretreatment section 11 and the surface is dried, the water content inside the sludge is not limited. Rates vary by season. However, since conditions are set so that they do not adhere or stick to each other, even if the water content changes, the above-mentioned rotary kiln body Kb
In the same manner. That is, when the water content is low, the fixed position F in the rotary kiln body Kb where the combustion conditions are satisfied moves to the upstream side (the flame moves to the upstream side),
When the water content is high, the drying time is required, so that the fixed position F where the combustion conditions are satisfied moves downstream (the flame moves downstream). This means that the discharge position of the combustible gas component released from the inside after the sludge is dried automatically moves upstream or downstream in the rotary kiln body Kb depending on the water content.

Gas combustion inside the rotary kiln main body Kb and gas exhaust from the main body Kb caused by the carbonization phenomenon are sucked by the exhaust treatment means 12, and the black smoke and odor are removed by the combustion block. After being treated in 12a, Cl components and the like pass through a cooling block 12b, are purified in a next neutralization block 12c, and are discharged out of the system from a filtration suction block 12d.

Next, a stir wall 31 as shown in FIG. 2 having a shape different from that of the above example is provided on the transfer wall 2 in the cylindrical body 1 of the rotary kiln body Kb of the carbonizing apparatus shown in FIG. Another example provided will be described. This stirring wall 31 is the transfer wall 2
The agitating wall 31 prevents the processing object M from entering inside the inner peripheral edge of the transport wall 2, and the front and rear transport walls 2. , 2
During the process, the mixture is stirred so that the front and back of the processed material M are inverted and rolled, so that the carbonized material is preferably burned without burning. That is, the heated hot air passes through the inside of the inner peripheral edge of the transfer wall 2 in the cylindrical body 1. When the processed material M enters inside the inner peripheral edge, the flame is directly applied. If not mixed, it will burn and a considerable amount will be ashed. Therefore, as described above, if the processed material M is stirred between the front and rear transport walls 2 and 2 so as not to enter inside the inner peripheral edge of the transport wall 2 (see FIGS. 3 and 4),
Since there is no burning, and the oxygen between the front and rear transport walls 2 and 2 is consumed for the combustion of the combustible gas discharged from the processing object M, the oxygen between the transport walls 2 and 2 is extremely low. In this state, when heated to a high temperature by the heated hot air passing inside the inner peripheral edge of the transfer wall 2, a flammable gas is further generated from the processed material M, and a so-called steamed state is formed to promote carbonization. Is done. Therefore, when the stirring wall 31 is used, it is not necessary to mix the ore in the treated material M in advance, and thus a high-purity carbide can be obtained. The shape of the stirring wall 31 is substantially semicircular in cross section. However, other than this, if the processed material M can be stirred in the same manner as described above, the stirring wall 31 has a substantially triangular cross section, a substantially trapezoidal cross section, or a substantially mountain-shaped cross section. Alternatively, the outer surfaces of these stirring walls, including the stirring walls having a substantially semicircular section in cross section, may be formed with irregularities such as corrugations. In addition to the carbonization apparatus of this example, FIG.
In order to obtain uniform charcoal even in the carbonization treatment device shown in (1), the shape of the treated material M such as sludge needs to be adjusted.

In the present invention, even if the processed material is non-sludge and high-moisture content chicken and livestock dung, the same carbonization treatment as in the above example can be carried out, and fir shell, okara, coffee beans and the like can be obtained. In the case of solid or fixed flammable products mainly of cereals, vegetables, and seafood, carbonization can be performed by applying the ore powder in advance to the object to be processed and then performing the same operation as in the above example. The above okara has a moisture content of 73%.
Therefore, raw garbage such as municipal garbage can be carbonized as sludge as it is, and since it has a high water content, it is once finely crushed into sludge and sludge is carbonized.

[0028]

The present invention is as described above. Wastes such as sludge having a high moisture content, and also amorphous and highly viscous sludge which could not be considered by conventional carbonization treatment are added to ore. The powder is kneaded to reduce the water content, and in this state, the cross-section is shaped through a molding machine, and a cylindrical transport wall is formed on the inner peripheral surface and a stirring wall that crosses the transport wall is partially formed. When the rotary kiln is continuously supplied in a predetermined unit amount while rotating the rotary kiln above the rotary kiln, a flame is blown into the rotary kiln from below the rotary kiln, and the sludge is ignited in the rotary kiln. Then, the blowing of the flame is stopped, and the gas in the rotary kiln is sucked from above the rotary kiln, detoxified and exhausted, so that the sludge carbide is continuously discharged from the lower portion of the rotary kirin. Since to be taken out, waste such as pretty energy saving manner sludge is the efficiency can be continuously carbonized. Therefore, the present invention is extremely useful especially as a method for treating sewage sludge which is in need of final treatment.

According to the carbonization method of the present invention, compared with the conventional method of converting sludge into a dewatered cake having a water content of about 70 to 80% and incinerating it in an incinerator, it consumes less oxygen because it is self-burning. Therefore, there is an effect that CO ₂ emission into the atmosphere can be reduced by as much as 35%.
This means that the amount of air used for combustion can be reduced, so that the size of the combustion block for combustion can be reduced, and the size of the cooling block, neutralization block, and filtration suction block must also be reduced. Is obtained.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a part of a cross section of a carbonization apparatus for carrying out a method of the present invention.

FIG. 2 is a view showing a transfer wall in the carbonization apparatus shown in FIG.
FIG. 2 is a partially enlarged perspective view of a transfer wall provided with a stirring wall different from that of FIG. 1.

FIG. 3 is a cross-sectional view of the cylindrical body 1 showing a state in which carbonization processing is performed by the apparatus shown in FIG.

FIG. 4 is a sectional view of the cylinder 1 showing a state where the cylinder 1 is rotated from the state shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical body 2 Conveying wall 3,31 Stirring wall 4 Heat insulation layer 5 Strip ring 6,7,8 Supporting roller 9 Gas burner 9a Flame injection port 10 Injection means 11 Pretreatment part 11a Molding part 11b Surface drying part 12 Exhaust treatment means 12a Combustion Block 12b Cooling block 12c Neutralization block 12d Filtration suction block Kb Rotary kiln body M Carbonized material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F23G 7/00 104 F23G 7/00 104A F-term (Reference) 3K061 AA08 AB01 AC02 BA05 CA01 DA03 DA04 DA17 DB06 DB14 GA05 GA10 KA02 KA05 KA13 KA16 KA28 3K065 AA07 AB02 AC02 BA06 BA10 CA04 CA11 3K078 AA05 BA09 BA21 BA26 CA01 4D059 AA03 BB05 BB14 BE53 BJ01 BK08 BK09 CC03 DA51 4H012 HA06

Claims (5)

[Claims] (1) Amorphous sludge containing water is kneaded with ore powder to reduce the water content. In this state, a cross-sectional shape is formed by passing through a molding machine, and each of the formed sludge is removed. After forming a surface state in which they do not adhere or stick to each other, the shaped sludge is formed into a cylindrical shape having a spiral conveying wall formed on an inner peripheral surface and a stirring wall crossing the conveying wall on a part of the conveying wall. The rotary kiln is continuously supplied at a predetermined unit amount while rotating the rotary kiln above the shape of the rotary kiln. (B) The inside of the rotary kiln from below the rotary kiln in the state of (a). When the sludge is ignited in the rotary kiln, the blowing of the flame is stopped. (C) From above the rotary kiln in the state of (a) or (b), the inside of the rotary kiln is Aspirate gas, detoxify and exhaust (D) A method of carbonizing sludge, wherein the carbides of the sludge are discharged from the lower part of the rotary giraffe by performing the operations (a) to (c). 2. The method for carbonizing sludge according to claim 1, wherein the shaped sludge is brought into a surface state in which the sludges are not adhered or adhered to each other by using a heating means or a blowing means or a heating and blowing means. 3. The agitating wall has a substantially semicircular cross section and is formed to protrude inward from an outer peripheral edge of the transporting wall.
Sludge carbonization method. 4. A solid or fixed-shaped combustible waste sprinkled with mineral powder is agitated by helically transporting the inner peripheral surface and traversing the transport wall with a part of the transport wall. Above the cylindrical rotary kiln on which the wall is formed, the rotary kiln is continuously supplied at a predetermined unit amount while rotating the rotary kiln. (B) From below the rotary kiln in the state of (a) above. A flame is blown into the rotary kiln, and when the sludge ignites in the rotary kiln, the blowing of the flame is stopped. (C) From above the rotary kiln placed in the state of (a) or (b), The gas inside the rotary kiln is sucked, detoxified, and exhausted. (D) Carrying out the lower part of the rotary kirin or the combustible exhaust by performing the operations (a) to (c). A method for carbonizing combustible waste, comprising: 5. The method for carbonizing combustible waste according to claim 4, wherein the agitating wall has a substantially semicircular cross section and bulges inward from an outer peripheral edge of the transfer wall.